Silicon is one of the most abundant elements in the Earth's crust. Nature has made use of silica in biological environments both as an essential nutrient and as the skeleton of certain marine organisms.1,2 Controlled silica formation has been accomplished in vitro using mammalian digestive enzymes.3 Although enzymes have been used to form carbohydrate-modified silicones, the cross-linking of silicone polymers using enzymes has not been examined.4 
Tin catalysts are often employed in the cross-linking of silicones, however, given the interest in using silicones as biomaterials, the use of potentially toxic tin compounds as catalysts can be limiting in this regard.5,6 Silicones and proteins are not incompatible species.5(c),7 Research conducted by both Morse et al. and Bassindale et al. has demonstrated the ability of silicatein and trypsin, respectively, to catalyze the hydrolysis and subsequent condensation of tetramethoxy- and tetraethoxysilanes.3,8 These experiments have focused almost exclusively on the ability of enzymes/proteins to generate inorganic silica species.